Table 3 Contact angles and surface free energy of polymer films

Water contact angle (θ, °)

Total surface free energy (γ_S)

Surface free energy, dispertion component (${\mathbf{\gamma }}_{{\mathbf{S}}^{\mathbf{d}}}$)

Surface free energy, polar component (${\mathbf{\gamma }}_{{\mathbf{S}}^{\mathbf{d}}}$)

Water uptake (w/w, %)

Polymer

“Smooth surface”

“Rough” surface

“Smooth surface”